Submit recent changes from internal branch, including "lite mode" for

C++ and Java.  See CHANGES.txt for more details.

10 files changed, 655 insertions, 386 deletions

diff --git a/src/google/protobuf/compiler/java/java_enum.cc b/src/google/protobuf/compiler/java/java_enum.cc
index 4aac6493..8ade50c9 100644
--- a/src/google/protobuf/compiler/java/java_enum.cc
+++ b/src/google/protobuf/compiler/java/java_enum.cc
@@ -67,14 +67,17 @@ EnumGenerator::EnumGenerator(const EnumDescriptor* descriptor)
 EnumGenerator::~EnumGenerator() {}
 
 void EnumGenerator::Generate(io::Printer* printer) {
-  bool is_own_file =
-    descriptor_->containing_type() == NULL &&
-    descriptor_->file()->options().java_multiple_files();
-  printer->Print(
-    "public $static$ enum $classname$\n"
-    "    implements com.google.protobuf.ProtocolMessageEnum {\n",
-    "static", is_own_file ? "" : "static",
-    "classname", descriptor_->name());
+  if (HasDescriptorMethods(descriptor_)) {
+    printer->Print(
+      "public enum $classname$\n"
+      "    implements com.google.protobuf.ProtocolMessageEnum {\n",
+      "classname", descriptor_->name());
+  } else {
+    printer->Print(
+      "public enum $classname$\n"
+      "    implements com.google.protobuf.Internal.EnumLite {\n",
+      "classname", descriptor_->name());
+  }
   printer->Indent();
 
   for (int i = 0; i < canonical_values_.size(); i++) {
@@ -126,63 +129,78 @@ void EnumGenerator::Generate(io::Printer* printer) {
     "    default: return null;\n"
     "  }\n"
     "}\n"
-    "\n");
+    "\n"
+    "public static com.google.protobuf.Internal.EnumLiteMap<$classname$>\n"
+    "    internalGetValueMap() {\n"
+    "  return internalValueMap;\n"
+    "}\n"
+    "private static com.google.protobuf.Internal.EnumLiteMap<$classname$>\n"
+    "    internalValueMap =\n"
+    "      new com.google.protobuf.Internal.EnumLiteMap<$classname$>() {\n"
+    "        public $classname$ findValueByNumber(int number) {\n"
+    "          return $classname$.valueOf(number)\n;"
+    "        }\n"
+    "      };\n"
+    "\n",
+    "classname", descriptor_->name());
 
   // -----------------------------------------------------------------
   // Reflection
 
-  printer->Print(
-    "public final com.google.protobuf.Descriptors.EnumValueDescriptor\n"
-    "    getValueDescriptor() {\n"
-    "  return getDescriptor().getValues().get(index);\n"
-    "}\n"
-    "public final com.google.protobuf.Descriptors.EnumDescriptor\n"
-    "    getDescriptorForType() {\n"
-    "  return getDescriptor();\n"
-    "}\n"
-    "public static final com.google.protobuf.Descriptors.EnumDescriptor\n"
-    "    getDescriptor() {\n");
-
-  // TODO(kenton):  Cache statically?  Note that we can't access descriptors
-  //   at module init time because it wouldn't work with descriptor.proto, but
-  //   we can cache the value the first time getDescriptor() is called.
-  if (descriptor_->containing_type() == NULL) {
+  if (HasDescriptorMethods(descriptor_)) {
     printer->Print(
-      "  return $file$.getDescriptor().getEnumTypes().get($index$);\n",
-      "file", ClassName(descriptor_->file()),
-      "index", SimpleItoa(descriptor_->index()));
-  } else {
-    printer->Print(
-      "  return $parent$.getDescriptor().getEnumTypes().get($index$);\n",
-      "parent", ClassName(descriptor_->containing_type()),
-      "index", SimpleItoa(descriptor_->index()));
-  }
+      "public final com.google.protobuf.Descriptors.EnumValueDescriptor\n"
+      "    getValueDescriptor() {\n"
+      "  return getDescriptor().getValues().get(index);\n"
+      "}\n"
+      "public final com.google.protobuf.Descriptors.EnumDescriptor\n"
+      "    getDescriptorForType() {\n"
+      "  return getDescriptor();\n"
+      "}\n"
+      "public static final com.google.protobuf.Descriptors.EnumDescriptor\n"
+      "    getDescriptor() {\n");
+
+    // TODO(kenton):  Cache statically?  Note that we can't access descriptors
+    //   at module init time because it wouldn't work with descriptor.proto, but
+    //   we can cache the value the first time getDescriptor() is called.
+    if (descriptor_->containing_type() == NULL) {
+      printer->Print(
+        "  return $file$.getDescriptor().getEnumTypes().get($index$);\n",
+        "file", ClassName(descriptor_->file()),
+        "index", SimpleItoa(descriptor_->index()));
+    } else {
+      printer->Print(
+        "  return $parent$.getDescriptor().getEnumTypes().get($index$);\n",
+        "parent", ClassName(descriptor_->containing_type()),
+        "index", SimpleItoa(descriptor_->index()));
+    }
 
-  printer->Print(
-    "}\n"
-    "\n"
-    "private static final $classname$[] VALUES = {\n"
-    "  ",
-    "classname", descriptor_->name());
+    printer->Print(
+      "}\n"
+      "\n"
+      "private static final $classname$[] VALUES = {\n"
+      "  ",
+      "classname", descriptor_->name());
+
+    for (int i = 0; i < descriptor_->value_count(); i++) {
+      printer->Print("$name$, ",
+        "name", descriptor_->value(i)->name());
+    }
 
-  for (int i = 0; i < descriptor_->value_count(); i++) {
-    printer->Print("$name$, ",
-      "name", descriptor_->value(i)->name());
+    printer->Print(
+      "\n"
+      "};\n"
+      "public static $classname$ valueOf(\n"
+      "    com.google.protobuf.Descriptors.EnumValueDescriptor desc) {\n"
+      "  if (desc.getType() != getDescriptor()) {\n"
+      "    throw new java.lang.IllegalArgumentException(\n"
+      "      \"EnumValueDescriptor is not for this type.\");\n"
+      "  }\n"
+      "  return VALUES[desc.getIndex()];\n"
+      "}\n",
+      "classname", descriptor_->name());
   }
 
-  printer->Print(
-    "\n"
-    "};\n"
-    "public static $classname$ valueOf(\n"
-    "    com.google.protobuf.Descriptors.EnumValueDescriptor desc) {\n"
-    "  if (desc.getType() != getDescriptor()) {\n"
-    "    throw new java.lang.IllegalArgumentException(\n"
-    "      \"EnumValueDescriptor is not for this type.\");\n"
-    "  }\n"
-    "  return VALUES[desc.getIndex()];\n"
-    "}\n",
-    "classname", descriptor_->name());
-
   // -----------------------------------------------------------------
 
   printer->Print(
@@ -194,14 +212,16 @@ void EnumGenerator::Generate(io::Printer* printer) {
     "}\n",
     "classname", descriptor_->name());
 
-  // Force the static initialization code for the file to run, since it may
-  // initialize static variables declared in this class.
-  printer->Print(
-    "\n"
-    "static {\n"
-    "  $file$.getDescriptor();\n"
-    "}\n",
-    "file", ClassName(descriptor_->file()));
+  if (HasDescriptorMethods(descriptor_)) {
+    // Force the static initialization code for the file to run, since it may
+    // initialize static variables declared in this class.
+    printer->Print(
+      "\n"
+      "static {\n"
+      "  $file$.getDescriptor();\n"
+      "}\n",
+      "file", ClassName(descriptor_->file()));
+  }
 
   printer->Outdent();
   printer->Print("}\n\n");
diff --git a/src/google/protobuf/compiler/java/java_enum_field.cc b/src/google/protobuf/compiler/java/java_enum_field.cc
index 2153042d..dc36e06e 100644
--- a/src/google/protobuf/compiler/java/java_enum_field.cc
+++ b/src/google/protobuf/compiler/java/java_enum_field.cc
@@ -39,7 +39,7 @@
 #include <google/protobuf/stubs/common.h>
 #include <google/protobuf/compiler/java/java_helpers.h>
 #include <google/protobuf/io/printer.h>
-#include <google/protobuf/wire_format_inl.h>
+#include <google/protobuf/wire_format.h>
 #include <google/protobuf/stubs/strutil.h>
 
 namespace google {
@@ -53,18 +53,13 @@ namespace {
 //   repeat code between this and the other field types.
 void SetEnumVariables(const FieldDescriptor* descriptor,
                       map<string, string>* variables) {
-  const EnumValueDescriptor* default_value;
-  default_value = descriptor->default_value_enum();
-
-  string type = ClassName(descriptor->enum_type());
-
   (*variables)["name"] =
     UnderscoresToCamelCase(descriptor);
   (*variables)["capitalized_name"] =
     UnderscoresToCapitalizedCamelCase(descriptor);
   (*variables)["number"] = SimpleItoa(descriptor->number());
-  (*variables)["type"] = type;
-  (*variables)["default"] = type + "." + default_value->name();
+  (*variables)["type"] = ClassName(descriptor->enum_type());
+  (*variables)["default"] = DefaultValue(descriptor);
   (*variables)["tag"] = SimpleItoa(internal::WireFormat::MakeTag(descriptor));
   (*variables)["tag_size"] = SimpleItoa(
       internal::WireFormat::TagSize(descriptor->number(), descriptor->type()));
@@ -132,10 +127,17 @@ void EnumFieldGenerator::
 GenerateParsingCode(io::Printer* printer) const {
   printer->Print(variables_,
     "int rawValue = input.readEnum();\n"
-    "$type$ value = $type$.valueOf(rawValue);\n"
-    "if (value == null) {\n"
-    "  unknownFields.mergeVarintField($number$, rawValue);\n"
-    "} else {\n"
+    "$type$ value = $type$.valueOf(rawValue);\n");
+  if (HasUnknownFields(descriptor_->containing_type())) {
+    printer->Print(variables_,
+      "if (value == null) {\n"
+      "  unknownFields.mergeVarintField($number$, rawValue);\n"
+      "} else {\n");
+  } else {
+    printer->Print(variables_,
+      "if (value != null) {\n");
+  }
+  printer->Print(variables_,
     "  set$capitalized_name$(value);\n"
     "}\n");
 }
@@ -185,7 +187,7 @@ GenerateMembers(io::Printer* printer) const {
     "}\n");
 
   if (descriptor_->options().packed() &&
-      descriptor_->file()->options().optimize_for() == FileOptions::SPEED) {
+      HasGeneratedMethods(descriptor_->containing_type())) {
     printer->Print(variables_,
       "private int $name$MemoizedSerializedSize;\n");
   }
@@ -272,10 +274,17 @@ GenerateParsingCode(io::Printer* printer) const {
   // Read and store the enum
   printer->Print(variables_,
     "int rawValue = input.readEnum();\n"
-    "$type$ value = $type$.valueOf(rawValue);\n"
-    "if (value == null) {\n"
-    "  unknownFields.mergeVarintField($number$, rawValue);\n"
-    "} else {\n"
+    "$type$ value = $type$.valueOf(rawValue);\n");
+  if (HasUnknownFields(descriptor_->containing_type())) {
+    printer->Print(variables_,
+      "if (value == null) {\n"
+      "  unknownFields.mergeVarintField($number$, rawValue);\n"
+      "} else {\n");
+  } else {
+    printer->Print(variables_,
+      "if (value != null) {\n");
+  }
+  printer->Print(variables_,
     "  add$capitalized_name$(value);\n"
     "}\n");
 
diff --git a/src/google/protobuf/compiler/java/java_extension.cc b/src/google/protobuf/compiler/java/java_extension.cc
index 302dcea4..4403220b 100644
--- a/src/google/protobuf/compiler/java/java_extension.cc
+++ b/src/google/protobuf/compiler/java/java_extension.cc
@@ -42,6 +42,39 @@ namespace protobuf {
 namespace compiler {
 namespace java {
 
+namespace {
+
+const char* TypeName(FieldDescriptor::Type field_type) {
+  switch (field_type) {
+    case FieldDescriptor::TYPE_INT32   : return "INT32";
+    case FieldDescriptor::TYPE_UINT32  : return "UINT32";
+    case FieldDescriptor::TYPE_SINT32  : return "SINT32";
+    case FieldDescriptor::TYPE_FIXED32 : return "FIXED32";
+    case FieldDescriptor::TYPE_SFIXED32: return "SFIXED32";
+    case FieldDescriptor::TYPE_INT64   : return "INT64";
+    case FieldDescriptor::TYPE_UINT64  : return "UINT64";
+    case FieldDescriptor::TYPE_SINT64  : return "SINT64";
+    case FieldDescriptor::TYPE_FIXED64 : return "FIXED64";
+    case FieldDescriptor::TYPE_SFIXED64: return "SFIXED64";
+    case FieldDescriptor::TYPE_FLOAT   : return "FLOAT";
+    case FieldDescriptor::TYPE_DOUBLE  : return "DOUBLE";
+    case FieldDescriptor::TYPE_BOOL    : return "BOOL";
+    case FieldDescriptor::TYPE_STRING  : return "STRING";
+    case FieldDescriptor::TYPE_BYTES   : return "BYTES";
+    case FieldDescriptor::TYPE_ENUM    : return "ENUM";
+    case FieldDescriptor::TYPE_GROUP   : return "GROUP";
+    case FieldDescriptor::TYPE_MESSAGE : return "MESSAGE";
+
+    // No default because we want the compiler to complain if any new
+    // types are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return NULL;
+}
+
+}
+
 ExtensionGenerator::ExtensionGenerator(const FieldDescriptor* descriptor)
   : descriptor_(descriptor) {
   if (descriptor_->extension_scope() != NULL) {
@@ -59,6 +92,7 @@ void ExtensionGenerator::Generate(io::Printer* printer) {
   vars["containing_type"] = ClassName(descriptor_->containing_type());
   vars["number"] = SimpleItoa(descriptor_->number());
   vars["constant_name"] = FieldConstantName(descriptor_);
+  vars["lite"] = HasDescriptorMethods(descriptor_->file()) ? "" : "Lite";
 
   JavaType java_type = GetJavaType(descriptor_);
   string singular_type;
@@ -79,13 +113,13 @@ void ExtensionGenerator::Generate(io::Printer* printer) {
   if (descriptor_->is_repeated()) {
     printer->Print(vars,
       "public static\n"
-      "  com.google.protobuf.GeneratedMessage.GeneratedExtension<\n"
+      "  com.google.protobuf.GeneratedMessage$lite$.GeneratedExtension<\n"
       "    $containing_type$,\n"
       "    java.util.List<$type$>> $name$;\n");
   } else {
     printer->Print(vars,
       "public static\n"
-      "  com.google.protobuf.GeneratedMessage.GeneratedExtension<\n"
+      "  com.google.protobuf.GeneratedMessage$lite$.GeneratedExtension<\n"
       "    $containing_type$,\n"
       "    $type$> $name$;\n");
   }
@@ -96,34 +130,71 @@ void ExtensionGenerator::GenerateInitializationCode(io::Printer* printer) {
   vars["name"] = UnderscoresToCamelCase(descriptor_);
   vars["scope"] = scope_;
   vars["index"] = SimpleItoa(descriptor_->index());
+  vars["extendee"] = ClassName(descriptor_->containing_type());
+  vars["default"] = descriptor_->is_repeated() ? "" : DefaultValue(descriptor_);
+  vars["number"] = SimpleItoa(descriptor_->number());
+  vars["type_constant"] = TypeName(descriptor_->type());
+  vars["packed"] = descriptor_->options().packed() ? "true" : "false";
+  vars["enum_map"] = "null";
+  vars["prototype"] = "null";
 
   JavaType java_type = GetJavaType(descriptor_);
   string singular_type;
   switch (java_type) {
     case JAVATYPE_MESSAGE:
       vars["type"] = ClassName(descriptor_->message_type());
+      vars["prototype"] = ClassName(descriptor_->message_type()) +
+                          ".getDefaultInstance()";
       break;
     case JAVATYPE_ENUM:
       vars["type"] = ClassName(descriptor_->enum_type());
+      vars["enum_map"] = ClassName(descriptor_->enum_type()) +
+                         ".internalGetValueMap()";
       break;
     default:
       vars["type"] = BoxedPrimitiveTypeName(java_type);
       break;
   }
 
-  if (descriptor_->is_repeated()) {
-    printer->Print(vars,
-      "$scope$.$name$ =\n"
-      "  com.google.protobuf.GeneratedMessage\n"
-      "    .newRepeatedGeneratedExtension(\n"
-      "      $scope$.getDescriptor().getExtensions().get($index$),\n"
-      "      $type$.class);\n");
+  if (HasDescriptorMethods(descriptor_->file())) {
+    if (descriptor_->is_repeated()) {
+      printer->Print(vars,
+        "$scope$.$name$ =\n"
+        "  com.google.protobuf.GeneratedMessage\n"
+        "    .newRepeatedGeneratedExtension(\n"
+        "      $scope$.getDescriptor().getExtensions().get($index$),\n"
+        "      $type$.class);\n");
+    } else {
+      printer->Print(vars,
+        "$scope$.$name$ =\n"
+        "  com.google.protobuf.GeneratedMessage.newGeneratedExtension(\n"
+        "    $scope$.getDescriptor().getExtensions().get($index$),\n"
+        "    $type$.class);\n");
+    }
   } else {
-    printer->Print(vars,
-      "$scope$.$name$ =\n"
-      "  com.google.protobuf.GeneratedMessage.newGeneratedExtension(\n"
-      "    $scope$.getDescriptor().getExtensions().get($index$),\n"
-      "    $type$.class);\n");
+    if (descriptor_->is_repeated()) {
+      printer->Print(vars,
+        "$scope$.$name$ =\n"
+        "  com.google.protobuf.GeneratedMessageLite\n"
+        "    .newRepeatedGeneratedExtension(\n"
+        "      $extendee$.getDefaultInstance(),\n"
+        "      $prototype$,\n"
+        "      $enum_map$,\n"
+        "      $number$,\n"
+        "      com.google.protobuf.WireFormat.FieldType.$type_constant$,\n"
+        "      $packed$);\n");
+    } else {
+      printer->Print(vars,
+        "$scope$.$name$ =\n"
+        "  com.google.protobuf.GeneratedMessageLite\n"
+        "    .newGeneratedExtension(\n"
+        "      $extendee$.getDefaultInstance(),\n"
+        "      $default$,\n"
+        "      $prototype$,\n"
+        "      $enum_map$,\n"
+        "      $number$,\n"
+        "      com.google.protobuf.WireFormat.FieldType.$type_constant$);\n");
+    }
   }
 }
 
diff --git a/src/google/protobuf/compiler/java/java_file.cc b/src/google/protobuf/compiler/java/java_file.cc
index 31d75be6..0e170b38 100644
--- a/src/google/protobuf/compiler/java/java_file.cc
+++ b/src/google/protobuf/compiler/java/java_file.cc
@@ -151,7 +151,9 @@ void FileGenerator::Generate(io::Printer* printer) {
 
   printer->Print(
     "public static void registerAllExtensions(\n"
-    "    com.google.protobuf.ExtensionRegistry registry) {\n");
+    "    com.google.protobuf.ExtensionRegistry$lite$ registry) {\n",
+    "lite", HasDescriptorMethods(file_) ? "" : "Lite");
+
   printer->Indent();
 
   for (int i = 0; i < file_->extension_count(); i++) {
@@ -195,8 +197,42 @@ void FileGenerator::Generate(io::Printer* printer) {
 
   printer->Print("\n");
 
-  // -----------------------------------------------------------------
+  if (HasDescriptorMethods(file_)) {
+    GenerateEmbeddedDescriptor(printer);
+  } else {
+    printer->Print(
+      "static {\n");
+    printer->Indent();
 
+    for (int i = 0; i < file_->message_type_count(); i++) {
+      // TODO(kenton):  Reuse MessageGenerator objects?
+      MessageGenerator(file_->message_type(i))
+        .GenerateStaticVariableInitializers(printer);
+    }
+
+    for (int i = 0; i < file_->extension_count(); i++) {
+      // TODO(kenton):  Reuse ExtensionGenerator objects?
+      ExtensionGenerator(file_->extension(i))
+        .GenerateInitializationCode(printer);
+    }
+
+    printer->Outdent();
+    printer->Print(
+      "}\n");
+  }
+
+  // Dummy function we can use to force the static initialization block to
+  // run.  Needed by inner classes.  Cannot be private due to
+  // java_multiple_files option.
+  printer->Print(
+    "\n"
+    "public static void internalForceInit() {}\n");
+
+  printer->Outdent();
+  printer->Print("}\n");
+}
+
+void FileGenerator::GenerateEmbeddedDescriptor(io::Printer* printer) {
   // Embed the descriptor.  We simply serialize the entire FileDescriptorProto
   // and embed it as a string literal, which is parsed and built into real
   // descriptors at initialization time.  We unfortunately have to put it in
@@ -310,9 +346,6 @@ void FileGenerator::Generate(io::Printer* printer) {
   printer->Outdent();
   printer->Print(
     "}\n");
-
-  printer->Outdent();
-  printer->Print("}\n");
 }
 
 template<typename GeneratorClass, typename DescriptorClass>
diff --git a/src/google/protobuf/compiler/java/java_file.h b/src/google/protobuf/compiler/java/java_file.h
index f1efd011..cb82cea2 100644
--- a/src/google/protobuf/compiler/java/java_file.h
+++ b/src/google/protobuf/compiler/java/java_file.h
@@ -81,6 +81,8 @@ class FileGenerator {
   string java_package_;
   string classname_;
 
+  void GenerateEmbeddedDescriptor(io::Printer* printer);
+
   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FileGenerator);
 };
 
diff --git a/src/google/protobuf/compiler/java/java_generator.cc b/src/google/protobuf/compiler/java/java_generator.cc
index 51af5f0d..8ed3affb 100644
--- a/src/google/protobuf/compiler/java/java_generator.cc
+++ b/src/google/protobuf/compiler/java/java_generator.cc
@@ -45,32 +45,6 @@ namespace protobuf {
 namespace compiler {
 namespace java {
 
-namespace {
-
-// Parses a set of comma-delimited name/value pairs, e.g.:
-//   "foo=bar,baz,qux=corge"
-// parses to the pairs:
-//   ("foo", "bar"), ("baz", ""), ("qux", "corge")
-void ParseOptions(const string& text, vector<pair<string, string> >* output) {
-  vector<string> parts;
-  SplitStringUsing(text, ",", &parts);
-
-  for (int i = 0; i < parts.size(); i++) {
-    string::size_type equals_pos = parts[i].find_first_of('=');
-    pair<string, string> value;
-    if (equals_pos == string::npos) {
-      value.first = parts[i];
-      value.second = "";
-    } else {
-      value.first = parts[i].substr(0, equals_pos);
-      value.second = parts[i].substr(equals_pos + 1);
-    }
-    output->push_back(value);
-  }
-}
-
-}  // namespace
-
 JavaGenerator::JavaGenerator() {}
 JavaGenerator::~JavaGenerator() {}
 
@@ -79,7 +53,7 @@ bool JavaGenerator::Generate(const FileDescriptor* file,
                              OutputDirectory* output_directory,
                              string* error) const {
   vector<pair<string, string> > options;
-  ParseOptions(parameter, &options);
+  ParseGeneratorParameter(parameter, &options);
 
   // -----------------------------------------------------------------
   // parse generator options
diff --git a/src/google/protobuf/compiler/java/java_helpers.cc b/src/google/protobuf/compiler/java/java_helpers.cc
index 6a107650..dc6748e3 100644
--- a/src/google/protobuf/compiler/java/java_helpers.cc
+++ b/src/google/protobuf/compiler/java/java_helpers.cc
@@ -37,6 +37,7 @@
 #include <google/protobuf/compiler/java/java_helpers.h>
 #include <google/protobuf/descriptor.pb.h>
 #include <google/protobuf/stubs/strutil.h>
+#include <google/protobuf/stubs/substitute.h>
 
 namespace google {
 namespace protobuf {
@@ -243,6 +244,72 @@ const char* BoxedPrimitiveTypeName(JavaType type) {
   return NULL;
 }
 
+bool AllAscii(const string& text) {
+  for (int i = 0; i < text.size(); i++) {
+    if ((text[i] & 0x80) != 0) {
+      return false;
+    }
+  }
+  return true;
+}
+
+string DefaultValue(const FieldDescriptor* field) {
+  // Switch on cpp_type since we need to know which default_value_* method
+  // of FieldDescriptor to call.
+  switch (field->cpp_type()) {
+    case FieldDescriptor::CPPTYPE_INT32:
+      return SimpleItoa(field->default_value_int32());
+    case FieldDescriptor::CPPTYPE_UINT32:
+      // Need to print as a signed int since Java has no unsigned.
+      return SimpleItoa(static_cast<int32>(field->default_value_uint32()));
+    case FieldDescriptor::CPPTYPE_INT64:
+      return SimpleItoa(field->default_value_int64()) + "L";
+    case FieldDescriptor::CPPTYPE_UINT64:
+      return SimpleItoa(static_cast<int64>(field->default_value_uint64())) +
+             "L";
+    case FieldDescriptor::CPPTYPE_DOUBLE:
+      return SimpleDtoa(field->default_value_double()) + "D";
+    case FieldDescriptor::CPPTYPE_FLOAT:
+      return SimpleFtoa(field->default_value_float()) + "F";
+    case FieldDescriptor::CPPTYPE_BOOL:
+      return field->default_value_bool() ? "true" : "false";
+    case FieldDescriptor::CPPTYPE_STRING:
+      if (field->type() == FieldDescriptor::TYPE_BYTES) {
+        if (field->has_default_value()) {
+          // See comments in Internal.java for gory details.
+          return strings::Substitute(
+            "com.google.protobuf.Internal.bytesDefaultValue(\"$0\")",
+            CEscape(field->default_value_string()));
+        } else {
+          return "com.google.protobuf.ByteString.EMPTY";
+        }
+      } else {
+        if (AllAscii(field->default_value_string())) {
+          // All chars are ASCII.  In this case CEscape() works fine.
+          return "\"" + CEscape(field->default_value_string()) + "\"";
+        } else {
+          // See comments in Internal.java for gory details.
+          return strings::Substitute(
+            "com.google.protobuf.Internal.stringDefaultValue(\"$0\")",
+            CEscape(field->default_value_string()));
+        }
+      }
+
+    case FieldDescriptor::CPPTYPE_ENUM:
+      return ClassName(field->enum_type()) + "." +
+             field->default_value_enum()->name();
+
+    case FieldDescriptor::CPPTYPE_MESSAGE:
+      return ClassName(field->message_type()) + ".getDefaultInstance()";
+
+    // No default because we want the compiler to complain if any new
+    // types are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return "";
+}
+
 }  // namespace java
 }  // namespace compiler
 }  // namespace protobuf
diff --git a/src/google/protobuf/compiler/java/java_helpers.h b/src/google/protobuf/compiler/java/java_helpers.h
index de3f883b..f1b643c3 100644
--- a/src/google/protobuf/compiler/java/java_helpers.h
+++ b/src/google/protobuf/compiler/java/java_helpers.h
@@ -36,6 +36,7 @@
 #define GOOGLE_PROTOBUF_COMPILER_JAVA_HELPERS_H__
 
 #include <string>
+#include <google/protobuf/descriptor.pb.h>
 #include <google/protobuf/descriptor.h>
 
 namespace google {
@@ -115,6 +116,35 @@ inline JavaType GetJavaType(const FieldDescriptor* field) {
 // types.
 const char* BoxedPrimitiveTypeName(JavaType type);
 
+string DefaultValue(const FieldDescriptor* field);
+
+// Does this message class keep track of unknown fields?
+inline bool HasUnknownFields(const Descriptor* descriptor) {
+  return descriptor->file()->options().optimize_for() !=
+           FileOptions::LITE_RUNTIME;
+}
+
+// Does this message class have generated parsing, serialization, and other
+// standard methods for which reflection-based fallback implementations exist?
+inline bool HasGeneratedMethods(const Descriptor* descriptor) {
+  return descriptor->file()->options().optimize_for() !=
+           FileOptions::CODE_SIZE;
+}
+
+// Does this message class have descriptor and reflection methods?
+inline bool HasDescriptorMethods(const Descriptor* descriptor) {
+  return descriptor->file()->options().optimize_for() !=
+           FileOptions::LITE_RUNTIME;
+}
+inline bool HasDescriptorMethods(const EnumDescriptor* descriptor) {
+  return descriptor->file()->options().optimize_for() !=
+           FileOptions::LITE_RUNTIME;
+}
+inline bool HasDescriptorMethods(const FileDescriptor* descriptor) {
+  return descriptor->options().optimize_for() !=
+           FileOptions::LITE_RUNTIME;
+}
+
 }  // namespace java
 }  // namespace compiler
 }  // namespace protobuf
diff --git a/src/google/protobuf/compiler/java/java_message.cc b/src/google/protobuf/compiler/java/java_message.cc
index c9cbd13f..f79546d6 100644
--- a/src/google/protobuf/compiler/java/java_message.cc
+++ b/src/google/protobuf/compiler/java/java_message.cc
@@ -41,7 +41,7 @@
 #include <google/protobuf/stubs/strutil.h>
 #include <google/protobuf/io/printer.h>
 #include <google/protobuf/io/coded_stream.h>
-#include <google/protobuf/wire_format_inl.h>
+#include <google/protobuf/wire_format.h>
 #include <google/protobuf/descriptor.pb.h>
 
 namespace google {
@@ -50,6 +50,7 @@ namespace compiler {
 namespace java {
 
 using internal::WireFormat;
+using internal::WireFormatLite;
 
 namespace {
 
@@ -153,38 +154,41 @@ MessageGenerator::MessageGenerator(const Descriptor* descriptor)
 MessageGenerator::~MessageGenerator() {}
 
 void MessageGenerator::GenerateStaticVariables(io::Printer* printer) {
-  // Because descriptor.proto (com.google.protobuf.DescriptorProtos) is
-  // used in the construction of descriptors, we have a tricky bootstrapping
-  // problem.  To help control static initialization order, we make sure all
-  // descriptors and other static data that depends on them are members of
-  // the outermost class in the file.  This way, they will be initialized in
-  // a deterministic order.
-
-  map<string, string> vars;
-  vars["identifier"] = UniqueFileScopeIdentifier(descriptor_);
-  vars["index"] = SimpleItoa(descriptor_->index());
-  vars["classname"] = ClassName(descriptor_);
-  if (descriptor_->containing_type() != NULL) {
-    vars["parent"] = UniqueFileScopeIdentifier(descriptor_->containing_type());
-  }
-  if (descriptor_->file()->options().java_multiple_files()) {
-    // We can only make these package-private since the classes that use them
-    // are in separate files.
-    vars["private"] = "";
-  } else {
-    vars["private"] = "private ";
-  }
+  if (HasDescriptorMethods(descriptor_)) {
+    // Because descriptor.proto (com.google.protobuf.DescriptorProtos) is
+    // used in the construction of descriptors, we have a tricky bootstrapping
+    // problem.  To help control static initialization order, we make sure all
+    // descriptors and other static data that depends on them are members of
+    // the outermost class in the file.  This way, they will be initialized in
+    // a deterministic order.
+
+    map<string, string> vars;
+    vars["identifier"] = UniqueFileScopeIdentifier(descriptor_);
+    vars["index"] = SimpleItoa(descriptor_->index());
+    vars["classname"] = ClassName(descriptor_);
+    if (descriptor_->containing_type() != NULL) {
+      vars["parent"] = UniqueFileScopeIdentifier(
+          descriptor_->containing_type());
+    }
+    if (descriptor_->file()->options().java_multiple_files()) {
+      // We can only make these package-private since the classes that use them
+      // are in separate files.
+      vars["private"] = "";
+    } else {
+      vars["private"] = "private ";
+    }
 
-  // The descriptor for this type.
-  printer->Print(vars,
-    "$private$static com.google.protobuf.Descriptors.Descriptor\n"
-    "  internal_$identifier$_descriptor;\n");
+    // The descriptor for this type.
+    printer->Print(vars,
+      "$private$static com.google.protobuf.Descriptors.Descriptor\n"
+      "  internal_$identifier$_descriptor;\n");
 
-  // And the FieldAccessorTable.
-  printer->Print(vars,
-    "$private$static\n"
-    "  com.google.protobuf.GeneratedMessage.FieldAccessorTable\n"
-    "    internal_$identifier$_fieldAccessorTable;\n");
+    // And the FieldAccessorTable.
+    printer->Print(vars,
+      "$private$static\n"
+      "  com.google.protobuf.GeneratedMessage.FieldAccessorTable\n"
+      "    internal_$identifier$_fieldAccessorTable;\n");
+  }
 
   // Generate static members for all nested types.
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
@@ -196,41 +200,44 @@ void MessageGenerator::GenerateStaticVariables(io::Printer* printer) {
 
 void MessageGenerator::GenerateStaticVariableInitializers(
     io::Printer* printer) {
-  map<string, string> vars;
-  vars["identifier"] = UniqueFileScopeIdentifier(descriptor_);
-  vars["index"] = SimpleItoa(descriptor_->index());
-  vars["classname"] = ClassName(descriptor_);
-  if (descriptor_->containing_type() != NULL) {
-    vars["parent"] = UniqueFileScopeIdentifier(descriptor_->containing_type());
-  }
+  if (HasDescriptorMethods(descriptor_)) {
+    map<string, string> vars;
+    vars["identifier"] = UniqueFileScopeIdentifier(descriptor_);
+    vars["index"] = SimpleItoa(descriptor_->index());
+    vars["classname"] = ClassName(descriptor_);
+    if (descriptor_->containing_type() != NULL) {
+      vars["parent"] = UniqueFileScopeIdentifier(
+          descriptor_->containing_type());
+    }
 
-  // The descriptor for this type.
-  if (descriptor_->containing_type() == NULL) {
-    printer->Print(vars,
-      "internal_$identifier$_descriptor =\n"
-      "  getDescriptor().getMessageTypes().get($index$);\n");
-  } else {
-    printer->Print(vars,
-      "internal_$identifier$_descriptor =\n"
-      "  internal_$parent$_descriptor.getNestedTypes().get($index$);\n");
-  }
+    // The descriptor for this type.
+    if (descriptor_->containing_type() == NULL) {
+      printer->Print(vars,
+        "internal_$identifier$_descriptor =\n"
+        "  getDescriptor().getMessageTypes().get($index$);\n");
+    } else {
+      printer->Print(vars,
+        "internal_$identifier$_descriptor =\n"
+        "  internal_$parent$_descriptor.getNestedTypes().get($index$);\n");
+    }
 
-  // And the FieldAccessorTable.
-  printer->Print(vars,
-    "internal_$identifier$_fieldAccessorTable = new\n"
-    "  com.google.protobuf.GeneratedMessage.FieldAccessorTable(\n"
-    "    internal_$identifier$_descriptor,\n"
-    "    new java.lang.String[] { ");
-  for (int i = 0; i < descriptor_->field_count(); i++) {
-    printer->Print(
-      "\"$field_name$\", ",
-      "field_name",
-        UnderscoresToCapitalizedCamelCase(descriptor_->field(i)));
+    // And the FieldAccessorTable.
+    printer->Print(vars,
+      "internal_$identifier$_fieldAccessorTable = new\n"
+      "  com.google.protobuf.GeneratedMessage.FieldAccessorTable(\n"
+      "    internal_$identifier$_descriptor,\n"
+      "    new java.lang.String[] { ");
+    for (int i = 0; i < descriptor_->field_count(); i++) {
+      printer->Print(
+        "\"$field_name$\", ",
+        "field_name",
+          UnderscoresToCapitalizedCamelCase(descriptor_->field(i)));
+    }
+    printer->Print("},\n"
+      "    $classname$.class,\n"
+      "    $classname$.Builder.class);\n",
+      "classname", ClassName(descriptor_));
   }
-  printer->Print("},\n"
-    "    $classname$.class,\n"
-    "    $classname$.Builder.class);\n",
-    "classname", ClassName(descriptor_));
 
   // Generate static member initializers for all nested types.
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
@@ -252,18 +259,35 @@ void MessageGenerator::Generate(io::Printer* printer) {
     descriptor_->file()->options().java_multiple_files();
 
   if (descriptor_->extension_range_count() > 0) {
-    printer->Print(
-      "public $static$ final class $classname$ extends\n"
-      "    com.google.protobuf.GeneratedMessage.ExtendableMessage<\n"
-      "      $classname$> {\n",
-      "static", is_own_file ? "" : "static",
-      "classname", descriptor_->name());
+    if (HasDescriptorMethods(descriptor_)) {
+      printer->Print(
+        "public $static$ final class $classname$ extends\n"
+        "    com.google.protobuf.GeneratedMessage.ExtendableMessage<\n"
+        "      $classname$> {\n",
+        "static", is_own_file ? "" : "static",
+        "classname", descriptor_->name());
+    } else {
+      printer->Print(
+        "public $static$ final class $classname$ extends\n"
+        "    com.google.protobuf.GeneratedMessageLite.ExtendableMessage<\n"
+        "      $classname$> {\n",
+        "static", is_own_file ? "" : "static",
+        "classname", descriptor_->name());
+    }
   } else {
-    printer->Print(
-      "public $static$ final class $classname$ extends\n"
-      "    com.google.protobuf.GeneratedMessage {\n",
-      "static", is_own_file ? "" : "static",
-      "classname", descriptor_->name());
+    if (HasDescriptorMethods(descriptor_)) {
+      printer->Print(
+        "public $static$ final class $classname$ extends\n"
+        "    com.google.protobuf.GeneratedMessage {\n",
+        "static", is_own_file ? "" : "static",
+        "classname", descriptor_->name());
+    } else {
+      printer->Print(
+        "public $static$ final class $classname$ extends\n"
+        "    com.google.protobuf.GeneratedMessageLite {\n",
+        "static", is_own_file ? "" : "static",
+        "classname", descriptor_->name());
+    }
   }
   printer->Indent();
   printer->Print(
@@ -280,20 +304,23 @@ void MessageGenerator::Generate(io::Printer* printer) {
     "}\n"
     "\n",
     "classname", descriptor_->name());
-  printer->Print(
-    "public static final com.google.protobuf.Descriptors.Descriptor\n"
-    "    getDescriptor() {\n"
-    "  return $fileclass$.internal_$identifier$_descriptor;\n"
-    "}\n"
-    "\n"
-    "@Override\n"
-    "protected com.google.protobuf.GeneratedMessage.FieldAccessorTable\n"
-    "    internalGetFieldAccessorTable() {\n"
-    "  return $fileclass$.internal_$identifier$_fieldAccessorTable;\n"
-    "}\n"
-    "\n",
-    "fileclass", ClassName(descriptor_->file()),
-    "identifier", UniqueFileScopeIdentifier(descriptor_));
+
+  if (HasDescriptorMethods(descriptor_)) {
+    printer->Print(
+      "public static final com.google.protobuf.Descriptors.Descriptor\n"
+      "    getDescriptor() {\n"
+      "  return $fileclass$.internal_$identifier$_descriptor;\n"
+      "}\n"
+      "\n"
+      "@Override\n"
+      "protected com.google.protobuf.GeneratedMessage.FieldAccessorTable\n"
+      "    internalGetFieldAccessorTable() {\n"
+      "  return $fileclass$.internal_$identifier$_fieldAccessorTable;\n"
+      "}\n"
+      "\n",
+      "fileclass", ClassName(descriptor_->file()),
+      "identifier", UniqueFileScopeIdentifier(descriptor_));
+  }
 
   // Nested types and extensions
   for (int i = 0; i < descriptor_->enum_type_count(); i++) {
@@ -318,7 +345,7 @@ void MessageGenerator::Generate(io::Printer* printer) {
     printer->Print("\n");
   }
 
-  if (descriptor_->file()->options().optimize_for() == FileOptions::SPEED) {
+  if (HasGeneratedMethods(descriptor_)) {
     GenerateIsInitialized(printer);
     GenerateMessageSerializationMethods(printer);
   }
@@ -326,12 +353,23 @@ void MessageGenerator::Generate(io::Printer* printer) {
   GenerateParseFromMethods(printer);
   GenerateBuilder(printer);
 
-  // Force the static initialization code for the file to run, since it may
-  // initialize static variables declared in this class.
+  if (HasDescriptorMethods(descriptor_)) {
+    // Force the static initialization code for the file to run, since it may
+    // initialize static variables declared in this class.
+    printer->Print(
+      "\n"
+      "static {\n"
+      "  $file$.getDescriptor();\n"
+      "}\n",
+      "file", ClassName(descriptor_->file()));
+  }
+
+  // Force initialization of outer class.  Otherwise, nested extensions may
+  // not be initialized.
   printer->Print(
     "\n"
     "static {\n"
-    "  $file$.getDescriptor();\n"
+    "  $file$.internalForceInit();\n"
     "}\n",
     "file", ClassName(descriptor_->file()));
 
@@ -360,9 +398,18 @@ GenerateMessageSerializationMethods(io::Printer* printer) {
   printer->Indent();
 
   if (descriptor_->extension_range_count() > 0) {
-    printer->Print(
-      "com.google.protobuf.GeneratedMessage.ExtendableMessage\n"
-      "  .ExtensionWriter extensionWriter = newExtensionWriter();\n");
+    if (descriptor_->options().message_set_wire_format()) {
+      printer->Print(
+        "com.google.protobuf.GeneratedMessage$lite$.ExtendableMessage\n"
+        "  .ExtensionWriter extensionWriter =\n"
+        "    newMessageSetExtensionWriter();\n",
+        "lite", HasDescriptorMethods(descriptor_) ? "" : "Lite");
+    } else {
+      printer->Print(
+        "com.google.protobuf.GeneratedMessage$lite$.ExtendableMessage\n"
+        "  .ExtensionWriter extensionWriter = newExtensionWriter();\n",
+        "lite", HasDescriptorMethods(descriptor_) ? "" : "Lite");
+    }
   }
 
   // Merge the fields and the extension ranges, both sorted by field number.
@@ -380,12 +427,14 @@ GenerateMessageSerializationMethods(io::Printer* printer) {
     }
   }
 
-  if (descriptor_->options().message_set_wire_format()) {
-    printer->Print(
-      "getUnknownFields().writeAsMessageSetTo(output);\n");
-  } else {
-    printer->Print(
-      "getUnknownFields().writeTo(output);\n");
+  if (HasUnknownFields(descriptor_)) {
+    if (descriptor_->options().message_set_wire_format()) {
+      printer->Print(
+        "getUnknownFields().writeAsMessageSetTo(output);\n");
+    } else {
+      printer->Print(
+        "getUnknownFields().writeTo(output);\n");
+    }
   }
 
   printer->Outdent();
@@ -406,16 +455,23 @@ GenerateMessageSerializationMethods(io::Printer* printer) {
   }
 
   if (descriptor_->extension_range_count() > 0) {
-    printer->Print(
-      "size += extensionsSerializedSize();\n");
+    if (descriptor_->options().message_set_wire_format()) {
+      printer->Print(
+        "size += extensionsSerializedSizeAsMessageSet();\n");
+    } else {
+      printer->Print(
+        "size += extensionsSerializedSize();\n");
+    }
   }
 
-  if (descriptor_->options().message_set_wire_format()) {
-    printer->Print(
-      "size += getUnknownFields().getSerializedSizeAsMessageSet();\n");
-  } else {
-    printer->Print(
-      "size += getUnknownFields().getSerializedSize();\n");
+  if (HasUnknownFields(descriptor_)) {
+    if (descriptor_->options().message_set_wire_format()) {
+      printer->Print(
+        "size += getUnknownFields().getSerializedSizeAsMessageSet();\n");
+    } else {
+      printer->Print(
+        "size += getUnknownFields().getSerializedSize();\n");
+    }
   }
 
   printer->Outdent();
@@ -439,7 +495,7 @@ GenerateParseFromMethods(io::Printer* printer) {
     "}\n"
     "public static $classname$ parseFrom(\n"
     "    com.google.protobuf.ByteString data,\n"
-    "    com.google.protobuf.ExtensionRegistry extensionRegistry)\n"
+    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
     "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
     "  return newBuilder().mergeFrom(data, extensionRegistry)\n"
     "           .buildParsed();\n"
@@ -450,7 +506,7 @@ GenerateParseFromMethods(io::Printer* printer) {
     "}\n"
     "public static $classname$ parseFrom(\n"
     "    byte[] data,\n"
-    "    com.google.protobuf.ExtensionRegistry extensionRegistry)\n"
+    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
     "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
     "  return newBuilder().mergeFrom(data, extensionRegistry)\n"
     "           .buildParsed();\n"
@@ -461,7 +517,7 @@ GenerateParseFromMethods(io::Printer* printer) {
     "}\n"
     "public static $classname$ parseFrom(\n"
     "    java.io.InputStream input,\n"
-    "    com.google.protobuf.ExtensionRegistry extensionRegistry)\n"
+    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
     "    throws java.io.IOException {\n"
     "  return newBuilder().mergeFrom(input, extensionRegistry)\n"
     "           .buildParsed();\n"
@@ -472,7 +528,7 @@ GenerateParseFromMethods(io::Printer* printer) {
     "}\n"
     "public static $classname$ parseDelimitedFrom(\n"
     "    java.io.InputStream input,\n"
-    "    com.google.protobuf.ExtensionRegistry extensionRegistry)\n"
+    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
     "    throws java.io.IOException {\n"
     "  return newBuilder().mergeDelimitedFrom(input, extensionRegistry)\n"
     "           .buildParsed();\n"
@@ -484,7 +540,7 @@ GenerateParseFromMethods(io::Printer* printer) {
     "}\n"
     "public static $classname$ parseFrom(\n"
     "    com.google.protobuf.CodedInputStream input,\n"
-    "    com.google.protobuf.ExtensionRegistry extensionRegistry)\n"
+    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
     "    throws java.io.IOException {\n"
     "  return newBuilder().mergeFrom(input, extensionRegistry)\n"
     "           .buildParsed();\n"
@@ -509,32 +565,57 @@ void MessageGenerator::GenerateSerializeOneExtensionRange(
 
 void MessageGenerator::GenerateBuilder(io::Printer* printer) {
   printer->Print(
-    "public static Builder newBuilder() { return new Builder(); }\n"
-    "public Builder newBuilderForType() { return new Builder(); }\n"
+    "public static Builder newBuilder() { return Builder.create(); }\n"
+    "public Builder newBuilderForType() { return newBuilder(); }\n"
     "public static Builder newBuilder($classname$ prototype) {\n"
-    "  return new Builder().mergeFrom(prototype);\n"
+    "  return newBuilder().mergeFrom(prototype);\n"
     "}\n"
     "public Builder toBuilder() { return newBuilder(this); }\n"
     "\n",
     "classname", ClassName(descriptor_));
 
   if (descriptor_->extension_range_count() > 0) {
-    printer->Print(
-      "public static final class Builder extends\n"
-      "    com.google.protobuf.GeneratedMessage.ExtendableBuilder<\n"
-      "      $classname$, Builder> {\n",
-      "classname", ClassName(descriptor_));
+    if (HasDescriptorMethods(descriptor_)) {
+      printer->Print(
+        "public static final class Builder extends\n"
+        "    com.google.protobuf.GeneratedMessage.ExtendableBuilder<\n"
+        "      $classname$, Builder> {\n",
+        "classname", ClassName(descriptor_));
+    } else {
+      printer->Print(
+        "public static final class Builder extends\n"
+        "    com.google.protobuf.GeneratedMessageLite.ExtendableBuilder<\n"
+        "      $classname$, Builder> {\n",
+        "classname", ClassName(descriptor_));
+    }
   } else {
-    printer->Print(
-      "public static final class Builder extends\n"
-      "    com.google.protobuf.GeneratedMessage.Builder<Builder> {\n",
-      "classname", ClassName(descriptor_));
+    if (HasDescriptorMethods(descriptor_)) {
+      printer->Print(
+        "public static final class Builder extends\n"
+        "    com.google.protobuf.GeneratedMessage.Builder<Builder> {\n",
+        "classname", ClassName(descriptor_));
+    } else {
+      printer->Print(
+        "public static final class Builder extends\n"
+        "    com.google.protobuf.GeneratedMessageLite.Builder<\n"
+        "      $classname$, Builder> {\n",
+        "classname", ClassName(descriptor_));
+    }
   }
   printer->Indent();
 
+  // By using a threadlocal queue, we do not have to worry about locking when
+  // accessing the queue.  Current JDKs implement this very efficiently, using
+  // no locks themselves to acquire the value when needed.
+  printer->Print(
+    "private static final "
+    "  com.google.protobuf.Internal.ThreadLocalQuickQueue<Builder> builders =\n"
+    "    new com.google.protobuf.Internal.ThreadLocalQuickQueue<Builder>();\n"
+    "\n");
+
   GenerateCommonBuilderMethods(printer);
 
-  if (descriptor_->file()->options().optimize_for() == FileOptions::SPEED) {
+  if (HasGeneratedMethods(descriptor_)) {
     GenerateBuilderParsingMethods(printer);
   }
 
@@ -553,10 +634,19 @@ void MessageGenerator::GenerateBuilder(io::Printer* printer) {
 
 void MessageGenerator::GenerateCommonBuilderMethods(io::Printer* printer) {
   printer->Print(
+    "private $classname$ result;\n"
+    "\n"
     "// Construct using $classname$.newBuilder()\n"
     "private Builder() {}\n"
     "\n"
-    "$classname$ result = new $classname$();\n"
+    "private static Builder create() {\n"
+    "  Builder builder = builders.get().poll();\n"
+    "  if (builder == null) {\n"
+    "    builder = new Builder();\n"
+    "  }\n"
+    "  builder.result = new $classname$();\n"
+    "  return builder;\n"
+    "}\n"
     "\n"
     "@Override\n"
     "protected $classname$ internalGetResult() {\n"
@@ -565,25 +655,38 @@ void MessageGenerator::GenerateCommonBuilderMethods(io::Printer* printer) {
     "\n"
     "@Override\n"
     "public Builder clear() {\n"
+    "  if (result == null) {\n"
+    "    throw new IllegalStateException(\n"
+    "      \"Cannot call clear() after build().\");\n"
+    "  }\n"
     "  result = new $classname$();\n"
     "  return this;\n"
     "}\n"
     "\n"
     "@Override\n"
     "public Builder clone() {\n"
-    "  return new Builder().mergeFrom(result);\n"
+    "  return create().mergeFrom(result);\n"
     "}\n"
-    "\n"
-    "@Override\n"
-    "public com.google.protobuf.Descriptors.Descriptor\n"
-    "    getDescriptorForType() {\n"
-    "  return $classname$.getDescriptor();\n"
-    "}\n"
-    "\n"
+    "\n",
+    "classname", ClassName(descriptor_));
+  if (HasDescriptorMethods(descriptor_)) {
+    printer->Print(
+      "@Override\n"
+      "public com.google.protobuf.Descriptors.Descriptor\n"
+      "    getDescriptorForType() {\n"
+      "  return $classname$.getDescriptor();\n"
+      "}\n"
+      "\n",
+      "classname", ClassName(descriptor_));
+  }
+  printer->Print(
     "public $classname$ getDefaultInstanceForType() {\n"
     "  return $classname$.getDefaultInstance();\n"
     "}\n"
-    "\n",
+    "\n"
+    "public boolean isInitialized() {\n"
+    "  return result.isInitialized();\n"
+    "}\n",
     "classname", ClassName(descriptor_));
 
   // -----------------------------------------------------------------
@@ -592,8 +695,7 @@ void MessageGenerator::GenerateCommonBuilderMethods(io::Printer* printer) {
     "public $classname$ build() {\n"
     // If result == null, we'll throw an appropriate exception later.
     "  if (result != null && !isInitialized()) {\n"
-    "    throw new com.google.protobuf.UninitializedMessageException(\n"
-    "      result);\n"
+    "    throw newUninitializedMessageException(result);\n"
     "  }\n"
     "  return buildPartial();\n"
     "}\n"
@@ -601,7 +703,7 @@ void MessageGenerator::GenerateCommonBuilderMethods(io::Printer* printer) {
     "private $classname$ buildParsed()\n"
     "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
     "  if (!isInitialized()) {\n"
-    "    throw new com.google.protobuf.UninitializedMessageException(\n"
+    "    throw newUninitializedMessageException(\n"
     "      result).asInvalidProtocolBufferException();\n"
     "  }\n"
     "  return buildPartial();\n"
@@ -610,7 +712,7 @@ void MessageGenerator::GenerateCommonBuilderMethods(io::Printer* printer) {
     "public $classname$ buildPartial() {\n"
     "  if (result == null) {\n"
     "    throw new IllegalStateException(\n"
-    "      \"build() has already been called on this Builder.\");"
+    "      \"build() has already been called on this Builder.\");\n"
     "  }\n",
     "classname", ClassName(descriptor_));
   printer->Indent();
@@ -623,6 +725,7 @@ void MessageGenerator::GenerateCommonBuilderMethods(io::Printer* printer) {
   printer->Print(
     "  $classname$ returnMe = result;\n"
     "  result = null;\n"
+    "  builders.get().offer(this);\n"
     "  return returnMe;\n"
     "}\n"
     "\n",
@@ -630,18 +733,25 @@ void MessageGenerator::GenerateCommonBuilderMethods(io::Printer* printer) {
 
   // -----------------------------------------------------------------
 
-  if (descriptor_->file()->options().optimize_for() == FileOptions::SPEED) {
+  if (HasGeneratedMethods(descriptor_)) {
+    // MergeFrom(Message other) requires the ability to distinguish the other
+    // messages type by its descriptor.
+    if (HasDescriptorMethods(descriptor_)) {
+      printer->Print(
+        "@Override\n"
+        "public Builder mergeFrom(com.google.protobuf.Message other) {\n"
+        "  if (other instanceof $classname$) {\n"
+        "    return mergeFrom(($classname$)other);\n"
+        "  } else {\n"
+        "    super.mergeFrom(other);\n"
+        "    return this;\n"
+        "  }\n"
+        "}\n"
+        "\n",
+        "classname", ClassName(descriptor_));
+    }
+
     printer->Print(
-      "@Override\n"
-      "public Builder mergeFrom(com.google.protobuf.Message other) {\n"
-      "  if (other instanceof $classname$) {\n"
-      "    return mergeFrom(($classname$)other);\n"
-      "  } else {\n"
-      "    super.mergeFrom(other);\n"
-      "    return this;\n"
-      "  }\n"
-      "}\n"
-      "\n"
       "public Builder mergeFrom($classname$ other) {\n"
       // Optimization:  If other is the default instance, we know none of its
       //   fields are set so we can skip the merge.
@@ -661,8 +771,12 @@ void MessageGenerator::GenerateCommonBuilderMethods(io::Printer* printer) {
         "  this.mergeExtensionFields(other);\n");
     }
 
+    if (HasUnknownFields(descriptor_)) {
+      printer->Print(
+        "  this.mergeUnknownFields(other.getUnknownFields());\n");
+    }
+
     printer->Print(
-      "  this.mergeUnknownFields(other.getUnknownFields());\n"
       "  return this;\n"
       "}\n"
       "\n");
@@ -678,23 +792,19 @@ void MessageGenerator::GenerateBuilderParsingMethods(io::Printer* printer) {
   printer->Print(
     "@Override\n"
     "public Builder mergeFrom(\n"
-    "    com.google.protobuf.CodedInputStream input)\n"
-    "    throws java.io.IOException {\n"
-    "  return mergeFrom(input,\n"
-    "    com.google.protobuf.ExtensionRegistry.getEmptyRegistry());\n"
-    "}\n"
-    "\n"
-    "@Override\n"
-    "public Builder mergeFrom(\n"
     "    com.google.protobuf.CodedInputStream input,\n"
-    "    com.google.protobuf.ExtensionRegistry extensionRegistry)\n"
+    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
     "    throws java.io.IOException {\n");
   printer->Indent();
 
+  if (HasUnknownFields(descriptor_)) {
+    printer->Print(
+      "com.google.protobuf.UnknownFieldSet.Builder unknownFields =\n"
+      "  com.google.protobuf.UnknownFieldSet.newBuilder(\n"
+      "    this.getUnknownFields());\n");
+  }
+
   printer->Print(
-    "com.google.protobuf.UnknownFieldSet.Builder unknownFields =\n"
-    "  com.google.protobuf.UnknownFieldSet.newBuilder(\n"
-    "    this.getUnknownFields());\n"
     "while (true) {\n");
   printer->Indent();
 
@@ -703,22 +813,34 @@ void MessageGenerator::GenerateBuilderParsingMethods(io::Printer* printer) {
     "switch (tag) {\n");
   printer->Indent();
 
-  printer->Print(
-    "case 0:\n"          // zero signals EOF / limit reached
-    "  this.setUnknownFields(unknownFields.build());\n"
-    "  return this;\n"
-    "default: {\n"
-    "  if (!parseUnknownField(input, unknownFields,\n"
-    "                         extensionRegistry, tag)) {\n"
-    "    this.setUnknownFields(unknownFields.build());\n"
-    "    return this;\n"   // it's an endgroup tag
-    "  }\n"
-    "  break;\n"
-    "}\n");
+  if (HasUnknownFields(descriptor_)) {
+    printer->Print(
+      "case 0:\n"          // zero signals EOF / limit reached
+      "  this.setUnknownFields(unknownFields.build());\n"
+      "  return this;\n"
+      "default: {\n"
+      "  if (!parseUnknownField(input, unknownFields,\n"
+      "                         extensionRegistry, tag)) {\n"
+      "    this.setUnknownFields(unknownFields.build());\n"
+      "    return this;\n"   // it's an endgroup tag
+      "  }\n"
+      "  break;\n"
+      "}\n");
+  } else {
+    printer->Print(
+      "case 0:\n"          // zero signals EOF / limit reached
+      "  return this;\n"
+      "default: {\n"
+      "  if (!parseUnknownField(input, extensionRegistry, tag)) {\n"
+      "    return this;\n"   // it's an endgroup tag
+      "  }\n"
+      "  break;\n"
+      "}\n");
+  }
 
   for (int i = 0; i < descriptor_->field_count(); i++) {
     const FieldDescriptor* field = sorted_fields[i];
-    uint32 tag = WireFormat::MakeTag(field->number(),
+    uint32 tag = WireFormatLite::MakeTag(field->number(),
       WireFormat::WireTypeForField(field));
 
     printer->Print(
diff --git a/src/google/protobuf/compiler/java/java_primitive_field.cc b/src/google/protobuf/compiler/java/java_primitive_field.cc
index 798e8608..327c2053 100644
--- a/src/google/protobuf/compiler/java/java_primitive_field.cc
+++ b/src/google/protobuf/compiler/java/java_primitive_field.cc
@@ -39,9 +39,8 @@
 #include <google/protobuf/stubs/common.h>
 #include <google/protobuf/compiler/java/java_helpers.h>
 #include <google/protobuf/io/printer.h>
-#include <google/protobuf/wire_format_inl.h>
+#include <google/protobuf/wire_format.h>
 #include <google/protobuf/stubs/strutil.h>
-#include <google/protobuf/stubs/substitute.h>
 
 namespace google {
 namespace protobuf {
@@ -49,6 +48,7 @@ namespace compiler {
 namespace java {
 
 using internal::WireFormat;
+using internal::WireFormatLite;
 
 namespace {
 
@@ -121,16 +121,6 @@ const char* GetCapitalizedType(const FieldDescriptor* field) {
   return NULL;
 }
 
-bool AllPrintableAscii(const string& text) {
-  // Cannot use isprint() because it's locale-specific.  :(
-  for (int i = 0; i < text.size(); i++) {
-    if ((text[i] < 0x20) || text[i] >= 0x7F) {
-      return false;
-    }
-  }
-  return true;
-}
-
 // For encodings with fixed sizes, returns that size in bytes.  Otherwise
 // returns -1.
 int FixedSize(FieldDescriptor::Type type) {
@@ -141,14 +131,14 @@ int FixedSize(FieldDescriptor::Type type) {
     case FieldDescriptor::TYPE_UINT64  : return -1;
     case FieldDescriptor::TYPE_SINT32  : return -1;
     case FieldDescriptor::TYPE_SINT64  : return -1;
-    case FieldDescriptor::TYPE_FIXED32 : return WireFormat::kFixed32Size;
-    case FieldDescriptor::TYPE_FIXED64 : return WireFormat::kFixed64Size;
-    case FieldDescriptor::TYPE_SFIXED32: return WireFormat::kSFixed32Size;
-    case FieldDescriptor::TYPE_SFIXED64: return WireFormat::kSFixed64Size;
-    case FieldDescriptor::TYPE_FLOAT   : return WireFormat::kFloatSize;
-    case FieldDescriptor::TYPE_DOUBLE  : return WireFormat::kDoubleSize;
-
-    case FieldDescriptor::TYPE_BOOL    : return WireFormat::kBoolSize;
+    case FieldDescriptor::TYPE_FIXED32 : return WireFormatLite::kFixed32Size;
+    case FieldDescriptor::TYPE_FIXED64 : return WireFormatLite::kFixed64Size;
+    case FieldDescriptor::TYPE_SFIXED32: return WireFormatLite::kSFixed32Size;
+    case FieldDescriptor::TYPE_SFIXED64: return WireFormatLite::kSFixed64Size;
+    case FieldDescriptor::TYPE_FLOAT   : return WireFormatLite::kFloatSize;
+    case FieldDescriptor::TYPE_DOUBLE  : return WireFormatLite::kDoubleSize;
+
+    case FieldDescriptor::TYPE_BOOL    : return WireFormatLite::kBoolSize;
     case FieldDescriptor::TYPE_ENUM    : return -1;
 
     case FieldDescriptor::TYPE_STRING  : return -1;
@@ -163,64 +153,6 @@ int FixedSize(FieldDescriptor::Type type) {
   return -1;
 }
 
-string DefaultValue(const FieldDescriptor* field) {
-  // Switch on cpp_type since we need to know which default_value_* method
-  // of FieldDescriptor to call.
-  switch (field->cpp_type()) {
-    case FieldDescriptor::CPPTYPE_INT32:
-      return SimpleItoa(field->default_value_int32());
-    case FieldDescriptor::CPPTYPE_UINT32:
-      // Need to print as a signed int since Java has no unsigned.
-      return SimpleItoa(static_cast<int32>(field->default_value_uint32()));
-    case FieldDescriptor::CPPTYPE_INT64:
-      return SimpleItoa(field->default_value_int64()) + "L";
-    case FieldDescriptor::CPPTYPE_UINT64:
-      return SimpleItoa(static_cast<int64>(field->default_value_uint64())) +
-             "L";
-    case FieldDescriptor::CPPTYPE_DOUBLE:
-      return SimpleDtoa(field->default_value_double()) + "D";
-    case FieldDescriptor::CPPTYPE_FLOAT:
-      return SimpleFtoa(field->default_value_float()) + "F";
-    case FieldDescriptor::CPPTYPE_BOOL:
-      return field->default_value_bool() ? "true" : "false";
-    case FieldDescriptor::CPPTYPE_STRING: {
-      bool isBytes = field->type() == FieldDescriptor::TYPE_BYTES;
-
-      if (!isBytes && AllPrintableAscii(field->default_value_string())) {
-        // All chars are ASCII and printable.  In this case CEscape() works
-        // fine (it will only escape quotes and backslashes).
-        // Note:  If this "optimization" is removed, DescriptorProtos will
-        //   no longer be able to initialize itself due to bootstrapping
-        //   problems.
-        return "\"" + CEscape(field->default_value_string()) + "\"";
-      }
-
-      if (isBytes && !field->has_default_value()) {
-        return "com.google.protobuf.ByteString.EMPTY";
-      }
-
-      // Escaping strings correctly for Java and generating efficient
-      // initializers for ByteStrings are both tricky.  We can sidestep the
-      // whole problem by just grabbing the default value from the descriptor.
-      return strings::Substitute(
-        "(($0) $1.getDescriptor().getFields().get($2).getDefaultValue())",
-        isBytes ? "com.google.protobuf.ByteString" : "java.lang.String",
-        ClassName(field->containing_type()), field->index());
-    }
-
-    case FieldDescriptor::CPPTYPE_ENUM:
-    case FieldDescriptor::CPPTYPE_MESSAGE:
-      GOOGLE_LOG(FATAL) << "Can't get here.";
-      return "";
-
-    // No default because we want the compiler to complain if any new
-    // types are added.
-  }
-
-  GOOGLE_LOG(FATAL) << "Can't get here.";
-  return "";
-}
-
 void SetPrimitiveVariables(const FieldDescriptor* descriptor,
                            map<string, string>* variables) {
   (*variables)["name"] =
@@ -285,8 +217,17 @@ GenerateBuilderMembers(io::Printer* printer) const {
     "  return this;\n"
     "}\n"
     "public Builder clear$capitalized_name$() {\n"
-    "  result.has$capitalized_name$ = false;\n"
-    "  result.$name$_ = $default$;\n"
+    "  result.has$capitalized_name$ = false;\n");
+  if (descriptor_->cpp_type() == FieldDescriptor::CPPTYPE_STRING) {
+    // The default value is not a simple literal so we want to avoid executing
+    // it multiple times.  Instead, get the default out of the default instance.
+    printer->Print(variables_,
+      "  result.$name$_ = getDefaultInstance().get$capitalized_name$();\n");
+  } else {
+    printer->Print(variables_,
+      "  result.$name$_ = $default$;\n");
+  }
+  printer->Print(variables_,
     "  return this;\n"
     "}\n");
 }
@@ -355,7 +296,7 @@ GenerateMembers(io::Printer* printer) const {
     "}\n");
 
   if (descriptor_->options().packed() &&
-      descriptor_->file()->options().optimize_for() == FileOptions::SPEED) {
+      HasGeneratedMethods(descriptor_->containing_type())) {
     printer->Print(variables_,
       "private int $name$MemoizedSerializedSize;\n");
   }